An organization that provides services via the Internet relies on the Internet to connect with users of its services. If there are problems along the path within the Internet (e.g., network problems, routing problems, congestion, etc.) between the organization's network and the users, then the users may experience problems accessing the services of the organization (e.g., service interruptions or slowdowns). Locating the source of such problems can be difficult. In some cases, network operators use test packets to try to locate the source of a problem. However, individual test packets may only be of limited use. For example, they may only indicate if a particular device is up or down, or they may only indicate the state of a particular device at a single instant in time.